Possibility of the use of exothermic-reactions heat from thermal destruction of biomass to increase the energy efficiency of the torrefaction process

Abstract

New results of investigation of exothermic effects accompanying the process of plant biomass torrefaction are presented in this paper, which is a continuation of experimental research carried out on the model lab-scale test-bench and devoted to the study of the exothermic effect. A distinctive feature of this work is using of a large-scale pilot torrefaction unit as a test item. This unit operation as close as possible simulates the processes taking place during industrial torrefaction. At this work stage a truncated version of the torrefaction unit was used (the upper hopper was demounted). Experimental data obtained on a pilot torrefaction unit confirm the possibility of exothermic reactions heat usage for process intensifying. It is shown that such operation mode provides increased unit productivity on conditions that gas piston engine is operating at a constant power mode. The characteristics of the fuel obtained in the proposed process organization, as well as the fuel obtained as a result of torrefaction process excluding the influence of exothermic effect heat, are compared. As the main directions of further research, the problem of low-temperature pyrolysis volatile products utilization and the development of operating parameters at a full-scale torrefaction unit have been chosen.